List of top Physics Questions on electrostatic potential and capacitance asked in JEE Main

A capacitor is made of two square plates each of side $'a'$ making a very small angle a between them, as shown in figure. The capacitance will be close to :

A parallel plate capacitor is of area $6 \; cm^2$ and a separation $3\, mm$. The gap is filled with three dielectric materials of equal thickness (see figure) with dielectric constants $K_1, = 10, K_2 = 12 $ and $K_3 = 14$. The dielectric constant of a material which when fully inserted in above capacitor, gives same capacitance would be :

A parallel plate capacitor with square plates is filled with four dielectrics of dielectric constants $K_1, K_2, K_3, K_4$ arranged as shown in the figure. The effective dielectric constant K will be :

A plane electromagnetic wave of frequency $50\, MHz$ travels in free space along the positive $x$-direction. At a particular point in space and time, $\vec{E} = 6.3 \hat{j} V/m$ . The corresponding magnetic field $\vec{B}$ , at that point will be:

A solid conducting sphere, having a charge $Q$, is surrounded by an uncharged conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface o f the hollow shell be $V$. If the shell is now given a charge of $-4\, Q$, the new potential difference between the same two surfaces is :

In the circuit shown, find $C$ if the effective capacitance of the whole circuit is to be $0.5 \mu F$. All values in the circuit are in $\mu F$.

In the figure shown, after the switch $'S'$ is turned from position $'A'$ to position $'B'$, the energy dissipated in the circuit in terms of capacitance $'C'$ and total charge $'Q'$ is:

In the figure shown below, the charge on the left plate of the $10 \; \mu F$ capacitor is $-30 \; \mu C$ . The charge on the right plate of the $6 \; \mu F$ capacitor is :

Voltage rating of a parallel plate capacitor is $500\,V$. Its dielectric can withstand a maximum electric field of $10^6$ V/m. The plate area is $10^{-4} \; m^2$. What is the dielectric constant is the capacitance is $15\, pF$ ? (given $\in_0 = 8.86 \times 10^{-12} C^2 / Nm^2$)

A parallel plate capacitor of capacitance $90\, pF$ is connected to a battery of emf $20\, V$. If a dielectric material of dielectric constant $ K = \frac{5}{3} $ is inserted between the plates, the magnitude of the induced charge will be :

A capacitance of $2 \, \mu F$ is required in an electrical circuit across a potential difference of $1.0\, kV$. A large number of $1 \, \mu F$ capacitors are available which can withstand a potential difference of not more than $300\, V$. The minimum number of capacitors required to achieve this is :

Figure shows a network of capacitors where the numbers indicates capacitances in micro Farad. The value of capacitance $C$ if the equivalent capacitance between point $A$ and $B$ is to be $1\, \mu F$ is :

A combination of capacitors is set up as shown in the figure. The magnitude of the electric field, due to a point charge $Q$ (having a charge equal to the sum of the charges on the $4 \, \mu F$ and $9 \, \mu F$ capacitors), at a point distant $30\, m$ from it, would equal :

In the given circuit, charge $Q_2 $ on the $2 \mu F $ capacitor changes as $C$ is varied from $1 \mu F $ to $3 \mu F. $ $Q_2 $ as a function of $'C'$ is given properly by (figures are drawn schematically and are not to scale)

A uniformly charged solid sphere of radius $R$ has potential $V _{0}\, 9$ measured with respect to $\infty$ ) on its surface. For this sphere the equipotential surfaces with potentials $\frac{3 V _{0}}{2}$, $\frac{5 V _{0}}{4}, \frac{3 V _{0}}{4}$ and $\frac{ V _{0}}{4}$ have radius $R _{1}, R _{2}, R _{3}$ and $R _{4}$ respectively. Then

In the following figure is shown a system of four capacitors connected across a $10\, V$ battery. Charge that will flow from switch $S$ when it is closed is

Assume that an electric field $\vec{E}=30 x^{2} \hat{i}$ exists in space. Then the potential difference $V_{A}-V_{O'}$ where $V_{O}$ is the potential at the origin and $V_{A}$ the potential at $x=2 \,m$ is

A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is $3 \times 10^4 \,V/m$, the charge density of the positive plate will be close to

A uniform electric field $\overrightarrow{E}$ exists between the plates of a charged condenser. A charged particle enters the space between the plates and perpendicular to $\overrightarrow{E}$. The path of the particle between the plates is a :

A charge Q is uniformly distributed over a long rod AB of length L as shown in the figure. The electric potential at the point O lying at distance L from the end A is

The surface charge density of a thin charged disc of radius $R$ is $\sigma$. The value of the electric field at the centre of the disc is $\frac{\sigma}{2 \in_{0}} \cdot$ With respect to the field at the centre, the electric field along the axis at a distance $R$ from the centre of the disc :